log -L: improve error message on malformed argument

diff --git a/sha1_name.c b/sha1_name.c
index 95f9f8fa1a72693757bbafe0f2a7773d8ae2de05..6d10f052b5050c64de5589733c2a8600e2ddb3dc 100644 (file)
--- a/sha1_name.c
+++ b/sha1_name.c
@@ -757,7 +757,7 @@ static int get_describe_name(const char *name, int len, unsigned char *sha1)
 
        for (cp = name + len - 1; name + 2 <= cp; cp--) {
                char ch = *cp;
-               if (hexval(ch) & ~0377) {
+               if (!isxdigit(ch)) {
                        /* We must be looking at g in "SOMETHING-g"
                         * for it to be describe output.
                         */